Quick-acting jet deflecting means for turbines of the pelton type



Feb. 8, 1955 H. BON 2,701,706

QUICK-ACTING JET DEFLECTING MEANS FOR TURBINEIS OF THE PELTON TYPE Filed March 1, 1949 2 Sheets-Sheet 1 m1 I d 21 INVEN TOR. Hem: Ban

HTTORNE Y BY filmy H. BON 2,701,706 QUICK-ACTING JET DEFLECTING MEANS FOR TURBINES OF THE PELTON TYPE 2 Sheets-Sheet 2 Feb. 8, 1955 Filed March 1, 1949 I NVENTOR. Hear: Ban BY @xflg g rumsma GOVERNOR mm lzla rurzame LOA D flTTORNEY United States Patent M QUICK-ACTING JET DEFLECTING MEANS FOR TURBINES OF THE PELTON TYPE Henri Ben, Saint-Nazaire, France, assignor to E'tablissements Neyrpic, Grenoble, France, a corporation of France Application March 1, 1949, Serial No. 78,898

Claims priority, application France March 2, 1948 Claims. (C1,.253-24) The present invention relates to control mechanisms for turbines of the Pelton type, and more particularly to means for insuring a more rapid response of the jet deflecting means to sudden and abnormal changes .in the operating conditions for the turbine, such as sudden .lessening of the load due to cutting out of a substantial demand for power, breaks in the power transmission line or other causes. The regulation of the speed of turbines of the Pelton type as heretofore practiced has involved the use of a needle valve which regulates the size of the jet directed against the rotatable runner and emitted .trom the injection nozzle in conjunction with a jet deflector which under certain conditions acts to deflect all or a part of the jet issuing from the fluid nozzle into a tail race. The needle valve and the deflector are both inter-connected with the turbine speed governing means. However, be cause of the necessity of .forcing the deflector into the jet whereas the needle valve is already .positioned within the jet nozzle in the line of flow, the maneuvering speed of the deflector is always much quicker than that of the needle valve. At the same time .it is important not to close the needle valve too rapidly, and, therefore, the

connections of the needle valve and the deflector to the turbine governing means are so arranged as to insure that the needle valve is caused .to move only after a certain interval of time when the deflector has already begun its movement into the jet.

While this arrangement is satisfactory for normal fluctuations of power demand or other normal variations in the operating conditions, it does not assure as prompt action as desired when there are abnormal changes in the operating conditions. For example, in the case of an assembly of electric generators feeding to a power line, it may happen that there will be a break in the line,

and this gives rise to danger of variations in the synchronism of the current because one or more of the turbines tends greatly to change its speed. In order to avoid this danger, it is customary to artificially readjust the system either by introducing a resistance in-to the line or by abruptly cutting off a certain part of the power being generated, for example, by uncoupling some of the gen-.

erators. Besides difiiculties involved in effecting necessary adjustments, all these expedients have the fault that there is still an undesirable time lapse before the regulation becomes eflective. The present invention has for an object to eliminate these inconveniences and assures the abrupt cutting off of supply of energy to the generators by providing an extremely rapid and prompt movement of the deflector to operative position.

According to the invention the instant and rapid movement of the deflector is assured by associating the deflector with means adapted when released to impose a strong force upon the deflector through appropriate mechanical connections urging the deflector to a jet engaging position independently of the normal regulatory movements brought about in the normal regulation of the operation of the turbine. The force which strongly urges the deflector to jet diverting position may be supplied by means of a driving element, such as a compressed spring acting upon a piston, connected to the deflector-actuating mechanism and normally held in compressed position by means of a latch or other restraining means.

The release of the quick-actuating mechanism is brought about by means of an electromagnet or equivalent means which responds to indications of a sudden change in power requirements or other abnormal incident to release the piston and permit it to move under the impulse of the spring and thus quickly bring the deflector to operative jet diverting position. The occurrence of abnormal change in operating conditions may be communicated electrically from a point remote from the site of the turbine and may'consist in the closing or the breaking of the circuit to the electromagnet thus energizing or deenergizing the electromagnet, as the case may be, and thereby bringing about unlatching of the means holding the spring-urged piston under restraint. Suitable means are also provided for restoring the quick-acting piston to reset position when it is no longer necessary to maintain the deflector in jet diverting position.

The quick-acting deflecting system may include a deflec tor that acts independently of an apart from the deflector employed in the normal regulation of the operation of the turbine or it may be incorporated into the present day system and act directly upon the deflector ordinarily provided. When this latter is done the arrangements are such as to permit the normal regulation of the jet without bringing the quick-acting mechanism into play. At the same time, the quick-acting mechanism is so connected as to be brought quickly into play and to take precedence in its action over the normal control connections of the deflector when an abnormal condition arises.

The invention will be more particularly described with reference to the accompanying drawing wherein:

Fig. 1 is a part longitudinal section showing one form taken by the quick-acting means for producing instant movement of the deflector to operative position;

Fig. 2 is a view in part side elevation and part section showing a somewhat modified form of the quick-acting means associated with a turbine nozzle and a deflector operated directly by such mechanism independently of the deflector system normally provided;

Fig. 3 is a view in part side elevation :and part section of a system similar to that shown in Fig. 2, except that in this case the quick-acting deflector is positioned to move into the path of the jet from below as contrasted with the movement downwardly from above that is insured by the system shown in Fig. 2;

Fig. 4 is a part side elevation and part section of still another modification of the system, in this case comprising interconnected actuating means operating on a single deflector and responsive respectively to the normal regulatory requirements and to the indication for instant deflection of the jet;

Fig. 5 is a part side elevation and part section of a system embodying two sets of regulatory controls for a single deflector as in Fig. 4 but differing therefrom in the substitution of a difierent form of interconnecting means for permitting the quick-acting mechanism to take over control in place of the normal regulating means when occasion for instant deflection becomes apparent;

Fig. 6 is a diagrammatic representation of the movements of the interconnected mechanism of Fig. 5 under conditions of normal regulation;

Fig. 7 is a diagrammatic representation of the movements of the interconnected actuating mechanism under conditions of abnormal or quick-acting regulation.

Fig. 1 shows a driving element comprising a cylinder 1 provided with end closures 2 and 3. A piston 4 is supported for sliding movement in the cylinder by a shaft 5 mounted in bearings 6 and 7 in the end closures 2 "and 3. The shaft '5 is connected through appropriate link members (not shown in Fig. 1) with the quick-acting deflector. The rapid movement of the deflector to jet diverting position is transmitted thereto through the shaft :5 under the action of the spring 8 bearing against the piston 4. The spring 8 is normally kept in a state of compression by a restraining member which, as shown in Fig. 1, consists of a pivotally mounted trigger member 9 having :arms 10 and 11 extending at an angle to one another.

When the trigger is cocked or in latched position the arm 10 is restrained against clockwise movement about the pivot 12 by a latch member 13.. As shown, this member includes an arm 14 pivoted at 15 and carrying a roller 16 at its outer end which engages a roller 17 carried by the arm 10. The arm 11 carries a roller 18 at its outer end which in the latched position bears against the shoulder 19 formed on the shaft 5. Control of the unlatching of the trigger member 9 is effected through an electromagnetic coil 20 acting as a solenoid on armature core 21. When the latch member and its solenoid connections are arranged in the relation to the trigger member 9 shown in Fig. 1, the coil 20 is energized through suitable electrical connections (not shown) in response to a sudden decrease in the load imposed on the turbine, thereby pulling the latch member 13 upwardly and releasing the member 9 for movement about its pivot under the urging of the spring 8 transmitted through shaft 5. It will be understood that the release of the latch member 13 may be similarly effected by mounting the latch in such relation to the trigger member 9 that the latch member will move downwardly under the influence of gravity when the coil 20 is de-energized in response to a sudden change in the operating characteristics of the turbine. The pivot point of the trigger 9 is slightly off center with respect to the axis of the shaft so that the trigger tends to move clockwise about its pivot under the urging of the spring 8 at all times while the trigger is maintained in latched position, and consequently as soon as the latch is released the trigger member will move quickly away from its holding position, thereby freeing the shaft 5 for sliding movement to the right, as shown, with the result that the quick-acting deflector is instantly moved to deflecting position. In order to check the movement of the piston 4 as it approaches the limit of its travel within the cylinder, means are provided for deadening or dampening further movement past the point where jet deflecting position of the deflector is insured. As shown in Fig. 1, such means consists of a spring 22 and a dash-pot arrangement comprising a second, smaller piston 23 mounted on the end of the shaft 5 which extends to the left of the piston 4 and reciprocates in the bearing 7. This smaller piston 23 is received within the annular space 24 provided in the re-entrant wall portion 24a of the end closure 3. The space 24 is constantly filled with oil or other liquid supplied from the reservoir 25.

When it is desired to reset the system, the piston is returned to the normal spring-urged position by forcing the shaft 5 and the related. elements backward against the action of the spring 8 until the latch 13 is again A brought into latching position. This may be done by any suitable means, as for example, by applying fluid pressure to the piston 4 through the inlet passage 26 from suitable connections (not shown) leading from a source of fluid under pressure.

Fig. 2 shows a somewhat modified form of the spring loaded quick-acting means associated through appropriate connections with the deflector operated thereby. According to this modification the piston 4 is mounted at one end of the shaft 5a and is urged to the left when viewed as shown, under the impulsion of the spring 8 disposed between the end wall 2a of the cylinder 1a and the adjacent face of the piston. A pivoted latch member 14a, when in latching position, bears against the inside face of the shoulder 19 carried by the shaft 5a. The latch member is moved to unlatching position through the action of the electromagnet-solenoid arrangement 20, 21, in the same manner as previously described with relation to Fig. 1. The shaft 5a is connected at its outer end through the link 28 to the ultra rapid deflector 29 which is pivotally supported by the bearing 30. Bumper pieces 22b formed of rubber or other appropriate resilient material are mounted on the end wall 3a of the cylinder 1a and serve to deaden the shock of the piston 4 when it is urged to the left under the impulsion of the spring 8.

Deflector 29 is mounted for movement independently of and in advance of the movement of the normal deflector 31. The latter is actuated by the rod 32 through suitable connections (not shown) in synchronism with the opening and closing movements of the needle valve 33.

As shown in Fig. 2 the quick-acting deflector 29 and the normally operated deflector 31 both move into the path of the issuing jet of fluid 34 from above.

In Fig. 3 is shown a modified arrangement wherein the quick-acting deflector moves into the path of the issuing jet from below. In this figure the arrangements and designations of the parts are the same as in Fig. 2, except that the spring 8 is mounted on the opposite side of the piston '4 so as to urge the latter toward the right when the latch 14b is moved to unlatching position under the urging of the solenoid 20, 21.

According to the modification of Fig. 4 a single deflector 35 is connected both to the means for introducing ultra-rapid deflecting action and to the means for moving the deflector in synchronism with the needle valve 33. As shown the deflector 35 is connected to the springloaded piston 4 through a lost-motion connection arrangement comprising a dash-pot 36 carried on the end of the shaft Sb and within which a piston 37 may be reciprocated. The piston 37 is mounted on the connecting rod 38 which is in turn pivotally connected to the link member 39 at 40. The link member 39 is pivotally connected at 41 to the end of the connecting rod 42 which in turn is connected to the arm 43 that is integral with the deflector 35 and moves the deflector about the pivot 44 in the course of the deflecting movements. The bell crank 45, pivotally supported at 46, at one end is connected to the link 39 and also to the connecting rod 42 at 41. At its opposite end the bell crank 45 is pivotally connected to a connecting rod 47 which in turn has a lost-motion connection to a member 48 connected with a link or control element 49 which is moved in synchronism with the movements of the needle valve 33 by means operatively controlled by the turbine governor as schematically illustrated in Fig. 4. The rod 47 is normally urged downwardly relative to member 48 under the action of the spring 50 so as to establish a substantially rigid connection between the control element 49 and the bell crank 45. The strength of the spring 50 is so adjusted as to insure that the rod 47 will remain in its fully extended position relative to member 48 during normal regulation of the deflector by reason of the pressure exerted by the spring against the annular shoulder 51 carried by the rod 47.

During the course of the normal regulation of the deflector 35 concomitantly with the normal regulating movements of the needle valve 33, the deflector 35 is moved toward and away from the deflecting position in accordance with the movements imparted to the rod 47 and transmitted thereby to the bell crank 45, the rod 42 and the deflector arm 43.

The quick-acting spring urged piston 4 remains inactive while the deflector is undergoing normal regulating movements in the manner above described. This is made possible by the dash-pot and piston connection 36, 37 interposed between shaft 5b and the link 39. Ports 52 permit a liquid confined in the dash-pot to flow past the piston as the piston is moved back and forth in the course of the normal regulating movements of the deflector.

In the case of an abnormal change in the load conditions or other change tending to improper operation of the turbine, current is transmitted through appropriate electrical connections schematically illustrated at 26a thus causing the electromagnet 20 to be energized and to move the latch member to unlatching position. Thereupon the piston 4 is moved quickly to the left, taking up lost motion in the dash-pot 36 and carrying with it the intermediate connections to the deflector arm 43 which is rocked clockwise, thus bringing the deflector immediately into operation. The spring 8 is made sufliciently strong to take over control of movement of the deflector and, as the shaft 5b and the intermediate connections are moved to the left, the crank 45 is rocked clockwise causing the connecting rod 47 to move upwardly against the compression of the spring 50 and relative to member 48 and control element 49. The position of the piston 37 within the dash-pot 36 will not be greatly changed during the course of this rapid movement. When it is desired to re-establish the cooked or reset condition of the quick-acting mechanism, fluid pressure will be introduced through the pipe 26 to urge the piston 4 to the right against the action of the spring 8 until the latch 14c can be again brought into engagement with the shoulder 19.

According to the modification shown in Fig. 5, the quick-acting mechanism operates similarly as in Fig. 1 but in this modification, as in that of Fig. 4, the quickacting mechanism and the normal regulating means are both connected to a single deflector 35.

In Fig. 5 the rod 49a as a control element is connected to the normal turbine speed regulator and transmits movement from this regulator to one arm of a bell crank 54 v enemas to which the rod 49a is connected at a. The bell crank 54 is supported for pivotal movement thereof at the pomt b on a. fixed support. At the point spaced from the fixed pivot 17 floating lever 53 is pivotally supported on the depending arm of the 'bell crank 54 and is connected at the point (1 spaced from the pivot point e to the deflector 35 through rod 42 and deflector arm 43. The lever 53 also is connected at the boint l1 spaced from the pivot point 0 to the quick-acting mechanism which includes the piston 4 in the cylinder 1b and the spring 8 blasing the piston 4 to move in the direction of the arrow m E 5.

The impulse imparted by the spring 8 .to the piston 4 upon release of latch 14d when actuated by the solenoid 20, 21 is transmitted through shaft b to floating lever 53 through its connection therewith at 11, causing the lever 53 to rotate about its center 'c. The sudden movement of the piston -4 produced by release from the latch is transmitted through the rod 42 to the deflector arm 43 and the deflector 35 to move the deflector to stream engaging position. As shown in Fig. 5 the lengths of the lever arms 12c and cd of the lever 53 have been taken as equal but they may be of difierent .lengths.

In each of the embodiments of Figs. 4 and 5 the connection to .the deflector from the driving element 4, 8 which is efiective as an emergency device under the control of the emergency control element 20, 21 to actuate the latch 14c, 14d does not include the normal control element 49, 49a responsive to variations in speed of the turbine. In these embodiments, when the latch 14c, 14d is disengaged, the bias means or spring 8 produces movement of the driving element 4., 5b, 36 .in a given direction. It the control element 49, 49a is in such .a position that the deflector is out of engagement with the stream, then the driving element becomes effective through the lost motion devices 36, 47, Fig. 4,, or the kinematic device of 54, 53, Fig. 5, and the connections to the deflector arm 43 to move the deflector 35 into engagement with the stream. In each of these embodiments such movements of the parts connected between the driving element and the deflector take place without producing movement of the control element 49, 49:: itself.

As shown diagrammatically in Fig. 6, during the regulating movements which take place in the normal operation of the turbine, the hell crank 54 of Fig. 5 rocks about a fixed center of rotation .b which at this time coincides with the point b. The point b is now maintained in fixed position inasmuch as its position is determined by the shaft 5b which is restrained from moving by the latch arm 14d. I

As shown diagrammatically in Fig. 7, when the quickacting mechanism is released and becomes operative upon the deflector 35 the bell crank .54 remains stationary and 0 becomes the center of rotation of the lever :53 so that as the shaft 5b is moved through a distance corresponding to movement of its pivotal connection 'to lever 53 from .b to b, the rod 42 is moved through .a corresponding distance represented by the displacement of the position of the point d as shown in Fig. 7. This is accompanied by practically instant movement of the deflector 35 to operative position.

It will be understood that various changes in the details of the construction and the arrangements of the parts may be made without departing from the invention and that the invention is not to be deemed as limited otherwise than as indicated in the appended claims.

I claim:

1. In combination with a hydraulic impulse turbine wheel, a nozzle positioned to direct a stream of liquid toward said turbine wheel, a deflector movable toward and away from a position in which said deflector engages said stream between the nozzle and the wheel and eflective when engaging the stream to deflect at least part of the stream away from the wheel, means responsive to the turbine speed to regulate the movement of said deflector toward and away from said stream, a lost-motion connection connecting said speed responsive means and said deflector, a spring in said connection normally effective to take up the lost motion therein so that the deflector is positioned by the speed'responsive means, a driving element, a mechanical connection between said driving element and said deflector in addition to said connection between said speed responsive means and said deflector and including a second lost-motion connection, means 6 biasing 'said driving element to move toward a position wherein the lost motion in said second connection "is taken up and said second con-nection connects said driving element to said deflector with said deflector in engagement with the stream so that the stream is deflected from the wheel, latch means normally holding said driving element against said biasing means in an inactive position wherein said deflector is positioned only by said speed responsive means, and means responsive to a sudden decrease in the turbine load and operatively connected to'said latch means to actuate said latch means to release saiddriving element.

2. Control apparatus for a hydraulic impulse turbine comprising a nozzle for directing a stream of liquid toward a turbine wheel, a deflector supported so as to be movable into and out of engagement with said stream and effective when engaging said stream to deflect at leastpart of the stream away from said turbine wheel, a control element 'of said turbine movable in agiven and the -reverse directions in response to variations in the turbine speed, a driving element movable in a given direction and reversely, -means biasing said driving element to move in its given direction of movement, means normally engagiing said driving element to hold said driving element against movement in its given direction under the action of said biasing means, means operatively connecting said control element to said deflector for normally effecting movement of said deflector into and out of engagement with said stream respectively upon movement of said control element in its given direction and in the reverse direction, means operatively connecting said driving element to said deflector "for eflecting movement of said deflector in the direction to engage said stream concomitantly with movement of said driving element in itsgiven direction upon disengagement of said holding means, means operatively connecting said elements to each other so as to provide for movement of said, elements relative to each other upon such movement of said deflector in the direction to engage the stream effected by either of said elements, said operative connection between said driving element and said deflector being additional to said operative connection between said control element and said deflector so as to be capable of transmitting said movement of said driving element in its given direction to said deflector concomitantly with said relative movement of said driving and control elements with respect to each other, and an emergency control element energized in response to a predetermined change in a condition .in the load to which the turbine is connected and operatively connected to said holding means for disengaging said holding meansfrom 'sa-id driving element to produce movement of said driving element in its given direction under the action of said biasing means and movement of said deflector into engagement with said stream.

3. Control apparatus for a hydraulic impulse turbine comprising a nozzle for directing a stream of liquid toward a turbine Wheel, .a deflector supported so as to 'be movable into and-out of engagement with said stream and effective when engaging said stream to deflect at least part of the stream away from said vturbine wheel, .a control element of said turbine movable in a given and the reverse direct-ions in response to variations in the turbine speed and operatively connected to said deflector for normally effecting movement of said deflector into and out of engagement with said stream respectively upon movement of said control element in said given and reverse directions, a lost motion device in said connection between said speed responsive control element and said deflector to provide for movement of said deflector relative to said control element, biasing means operatively connected to said lost motion device for actuating said lost motion device to move said deflector relative to said control element in the direction to move said deflector away from said stream, stop means in said connection limiting said movement of said deflector relative'to said control element under the action of said biasing means to provide for said normal movement of said deflector, a driving element movable in a given direction and reversely, biasing means connected to said driving element to bias said driving element to move in its given direction of movement, means normally engaging said driving element to hold said driving element against movement in said given direction under the action of its biasing means, means including a lost motion device operatively connecting said driving element to said deflector for effecting movement of said deflector toward said stream upon movement of said driving element in its given direction and providing for movement of said deflector relative to said driving element upon movement of said deflector effected by said speed responsive control element, said operative connection between said driving element and said deflector being additional to said operative connection between said control element and said deflector so as to be capable of transmitting said movement of said driving element in its given direction to said deflector concomitantly with actuation of said lost motion device in said connection between said control element and said deflector providing movement of said deflector relative to said control element, and an emergency control element energized in response to a predetermined change in a condition of the load to which said turbine is connected and operatively connected to said holding means for disengaging said holding means from said driving element to produce movement of said driving element in said given direction under the action of its biasing means and movement of said deflector into engagement with said stream.

4. Control apparatus for a hydraulic impulse turbine comprising a nozzle for directing a stream of liquid toward a turbine wheel, a deflector supported so as to be movable into and out of engagement with said stream and effective when engaging said stream to deflect at least part of the stream away from said turbine wheel, a control element of said turbine movable in a given and the reverse directions in response to variations in the turbine speed, an arm supported for pivotal movement thereof, means operatively connecting said speed responsive control element to said arm at a point on said arm spaced from said pivotal support of said arm for eflecting pivotal movement of said arm upon said movement of said speed responsive control element, a lever pivotally supported on said arm at a point spaced from said pivotal support of said arm, a driving element movable in a given direction and reversely, means operatively connecting said driving element to said lever at a point on said lever spaced from said pivotal support of said lever on said arm for effecting pivotal movement of said lever in a selected and the reverse directions relative to said arm upon movement of said driving element respectively in said given direction and reversely, means biasing said driving element to move in said given direction of movement, means normally engaging said driving element to hold said driving element against said movement in said given direction under the action of said biasing means, said connection of said driving element to said lever providing for movement of said lever relative to said driving element in said held position of said driving element upon pivotal movement of said arm on said pivotal support thereof, means operatively connecting said deflector to said lever at a point on said lever spaced from said point of pivotal support of said lever on said arm so as to move said deflector into and out of engagement with said stream concomitantly with movement of said lever respectively in said selected and the reverse directions, and an emergency control element energized in response to a predetermined change in a condition in the load to which said turbine is connected and operatively connected to said holding means for disengaging said holding means from said driving element to produce movement of said driving element in said given direction under the action of said biasing means and pivotal movement of said lever in said selected direction and movement of said deflector into engagement with said stream.

5. Control apparatus for a hydraulic turbine comprising a liquid flow control device having a member movable to and from a flow restricting position, a control element movable'in a given and the reverse directions in response to variations in the turbine speed, a driving element movable in a given direction and reversely, means biasing said driving element to move in its given direction of movement, means normally engaging said driving element to hold said driving element against movement in its given direction under the action of said biasing means, means operatively connecting said control element to said member of said flow control device for normally effecting movement of said member toward and away from said flow restricting position respectively upon movement of said control element in its given direction and in the reverse direction, means operatively connecting said driving element to said member for eflecting movement of said member in the direction toward said flow restricting position concomitantly with movement of said driving element in its given direction upon disengagement of said holding means, means operatively connecting said elements to each other so as to provide for movement of said elements relative to each other upon movement of said member toward said flow restricting position effected by either of said elements, said operative connection between said driving elernent and said member being additional to said operative connection of said control element to said member so as to be capable of transmitting said movement of said driving element in its given direction to said member concomitantly with said movement of said driving and control elements relative to each other, and an emergency control element energized in response to a predetermined change in a condition in the load to which the turbine is connected and operatively connected to said holding means for disengaging said holding means from said driving element to produce movement of said driving element in its given direction under the action of said biasing means and movement of said member of said flow control device toward said flow restricting position thereof.

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